WO2024004354A1

WO2024004354A1 - Carbide production system and carbide production method

Info

Publication number: WO2024004354A1
Application number: PCT/JP2023/015778
Authority: WO
Inventors: 道則成澤
Original assignee: 株式会社Ihi
Priority date: 2022-06-27
Filing date: 2023-04-20
Publication date: 2024-01-04
Also published as: JP7435921B1

Abstract

The carbide production system (1) comprises a combustion furnace (10) that contains a combustion chamber (12) having a first biomass supply port (17) that supplies a first biomass and combusts the first biomass in air and a carbide recovery device (40), connected to the combustion furnace (10), that recovers carbide generated from a second biomass. The second biomass is heated by the combustion of the first biomass via a second biomass supply port (18) provided downstream from the first biomass supply port (17) and is supplied to a carbonization zone where low-concentration oxygen gas, having a lower oxygen concentration than air, is present due to combustion of the first biomass.

Description

Carbide production system and carbide production method

The present disclosure relates to a carbide production system and a carbide production method.

Conventionally, methods of producing charcoal by heating biomass have been known. By producing charred material from biomass, the carbon in the biomass is fixed as charred material, so it is possible to suppress the release of carbon dioxide into the atmosphere compared to when biomass is burned.

Patent Document 1 discloses a cylindrical main body, a lid that closes an upper opening of the main body, a partition plate with ventilation holes arranged at a position away from the bottom plate, and a space between the bottom plate and the partition plate. A self-combustion carbonization heat treatment apparatus is disclosed that includes an air supply path that introduces air into an air supply chamber formed in the air supply chamber. Further, Patent Document 1 discloses that a self-combustion carbonization heat treatment apparatus includes a plurality of air supply cylinders with ventilation holes that are erected on a partition plate in communication with the ventilation holes of the partition plate. There is.

Patent No. 6285588

The above-mentioned self-combustion carbonization heat treatment apparatus generates carbide in a batch manner, and requires separate cooling time and raw material input time when taking out the carbide, so continuous processing is not possible and productivity is low. In addition, in the self-combustion carbonization heat treatment apparatus, the raw material spontaneously burns in an oxygen-deficient state, and the raw material is carbonized in the same region as the combustion region. Therefore, the conditions for producing carbides may not be stable. In such a case, the biomass may be burned more than necessary, and the properties of the charred material may become unstable, such as a decrease in the amount of charred material obtained.

Therefore, an object of the present disclosure is to provide a carbide production system and a carbide production method that can continuously produce stable carbide from biomass.

A charcoal production system according to the present disclosure includes a combustion furnace that has a first biomass supply port that supplies a first biomass, and includes a combustion chamber that burns the first biomass with air; and a combustion furnace that is connected to the combustion furnace; It is equipped with a carbide recovery device for recovering generated carbide. The second biomass is heated by combustion of the first biomass through a second biomass supply port provided downstream of the first biomass supply port, and has an oxygen concentration lower than that of air due to the combustion of the first biomass. The carbonized region is supplied with low concentration oxygen gas.

The combustion furnace may be a vertical combustion furnace.

The combustion chamber may be provided with a second biomass supply port that supplies the second biomass into the combustion chamber. Carbide may be generated within the combustion chamber.

The combustion furnace and the carbide recovery device may be connected via a connecting flow path. The connecting channel may be provided with a second biomass supply port for supplying the second biomass into the connecting channel. Carbide may be generated within the connecting channel.

The combustion furnace and the carbide recovery device may be connected via a connecting flow path. The connecting channel may be provided with an air supply port for supplying air into the connecting channel.

The carbide recovery device may include a cyclone.

The carbide production system may further include a gas utilization device that utilizes gas discharged from the carbide recovery device. The carbide may be cooled in the carbide recovery device by gas derived from gas discharged from the carbide recovery device and cooled by heat exchange in the gas utilization device.

The carbide production method according to the present disclosure includes a step of burning the first biomass supplied to the combustion chamber of the combustion furnace with air. The method for producing carbide includes a carbonization region that is downstream of the first biomass, is heated by the combustion of the first biomass, and contains a low-concentration oxygen gas whose oxygen concentration is lower than that of air due to the combustion of the first biomass. The method includes a step of supplying a second biomass to the second biomass. The carbide production method includes a step of recovering carbide produced from the second biomass with a carbide recovery device connected to a combustion furnace.

According to the present disclosure, it is possible to provide a carbide production system and a carbide production method that can continuously produce stable carbide from biomass.

FIG. 1 is a schematic diagram showing a carbide manufacturing system according to one embodiment. FIG. 2 is a schematic diagram showing the state around the second biomass supply port. FIG. 3 is a cross-sectional view of FIG. 2 taken along line III--III. FIG. 4 is a schematic diagram showing the state around the second biomass supply port according to another embodiment. FIG. 5 is a cross-sectional view of FIG. 4 taken along the line VV. FIG. 6 is a schematic diagram showing the state around the second biomass supply port according to another embodiment. FIG. 7 is a cross-sectional view of FIG. 6 taken along line VII-VII. FIG. 8 is a schematic diagram showing a carbide manufacturing system according to one embodiment. FIG. 9 is a schematic diagram showing a carbide manufacturing system according to one embodiment.

Hereinafter, some exemplary embodiments will be described with reference to the drawings. Note that the dimensional ratios in the drawings are exaggerated for convenience of explanation and may differ from the actual ratios.

[First embodiment]
First, a carbide manufacturing system 1 according to a first embodiment will be explained using FIGS. 1 to 7. As shown in FIG. 1, a carbide production system 1 according to the present embodiment includes a combustion furnace 10 and a carbide recovery device 40. The combustion furnace 10 is configured to burn the first biomass. The carbide recovery device 40 recovers carbide. As described below, char is produced from the second biomass.

In this embodiment, the combustion furnace 10 is a vertical fluidized bed combustion furnace. Although a vertical combustion furnace is advantageous in that it does not require a large installation area, the combustion furnace 10 is not limited to a vertical combustion furnace, and may be a horizontal combustion furnace. Further, the combustion furnace 10 is not limited to a fluidized bed type combustion furnace, but may be a grate type combustion furnace or a rotary type combustion furnace such as a kiln type combustion furnace.

The combustion furnace 10 includes a wind box 11 and a combustion chamber 12 provided above the wind box 11 in the vertical direction. The wind box 11 is a room for supplying combustion air. The combustion chamber 12 is a chamber in which the first biomass is burned with air. The wind box 11 and the combustion chamber 12 are separated by an air distribution plate 13. The air distribution plate 13 has a plurality of first air supply holes 14 .

The plurality of first air supply holes 14 are first air supply ports that supply air to the combustion chamber 12. The air supplied through the first air supply hole 14 is primary air. The primary air is supplied to the fluidized medium 15 and is mainly used for combustion. Air supplied from the air supply section 20 is supplied to the combustion chamber 12 via the wind box 11 and the plurality of first air supply holes 14. In this embodiment, the aeration method of the combustion furnace 10 is a dispersion plate type, but it may be an aeration tube type or a combination thereof.

An air supply section 20 is connected to the wind box 11. The air supply section 20 includes an air flow path 21, an air intake port 22, and a blower 23. The air flow path 21 is provided with an air intake port 22 and a blower 23. Further, a flow rate adjusting damper 24 is provided in the air flow path 21 between the air intake port 22 and the blower 23. Further, a flow rate adjustment damper 25 is provided in the air flow path 21 between the blower 23 and the wind box 11. Then, by driving the blower 23 with the flow rate adjustment damper 24 and the flow rate adjustment damper 25 open, air can be continuously supplied to the wind box 11 from the air intake port 22.

In the combustion chamber 12, a fluidizing medium 15 is arranged above the air distribution plate 13. The fluidizing medium 15 may also contain inert particles such as silica sand. When air is supplied from the wind box 11 to the combustion chamber 12 through the first air supply hole 14 of the air distribution plate 13, the fluidized medium 15 becomes fluidized and forms a fluidized bed. The air ratio in the fluidized bed may be about 0.5 to 1.5.

The combustion chamber 12 is provided with a second air supply port 16, a first biomass supply port 17, a second biomass supply port 18a, and an exhaust port 19.

The second air supply port 16 is a supply port that supplies air to the combustion chamber 12. The second air supply port 16 is provided in a side wall of the combustion chamber 12 . The second air supply port 16 is provided above the first air supply hole 14 in the vertical direction and below the second biomass supply port 18a and the discharge port 19 in the vertical direction. The air supplied through the second air supply port 16 is secondary air. By supplying secondary air to the combustion chamber 12, staged combustion can be performed at a temperature higher than the combustion temperature of the primary air, so that it is possible to suppress the fluidized medium 15 from sticking due to heat. Further, the oxygen concentration in the carbonization region, which will be described later, can also be adjusted using secondary air.

An air flow path 21 is connected to the second air supply port 16. The air flow path 21 branches between the blower 23 and the flow rate adjustment damper 25. The branched air flow path 21 is provided with a flow rate adjustment damper 26 and a flow rate adjustment damper 27. By driving the blower 23 with the flow rate adjustment damper 24, flow rate adjustment damper 26, and flow rate adjustment damper 27 open, air is continuously supplied to the combustion chamber 12 from the air intake port 22 through the second air supply port 16. can be supplied.

The first biomass supply port 17 is a supply port that supplies the first biomass to the combustion chamber 12. Since the first biomass can be supplied to the combustion chamber 12 via the first biomass supply port 17, the first biomass can be continuously supplied to the combustion chamber 12. Biomass is positioned as a renewable energy, and based on the concept of carbon neutrality, it is believed that burning biomass will not lead to an increase in carbon dioxide released into the atmosphere. By burning the first biomass, the use of fossil fuels can be reduced and the release of carbon dioxide into the atmosphere can be suppressed.

The first biomass supply port 17 is provided in the side wall that constitutes the combustion chamber 12. The first biomass supply port 17 is provided above the first air supply hole 14 in the vertical direction. A first biomass supply section 30 that supplies the first biomass to the combustion chamber 12 of the combustion furnace 10 is connected to the first biomass supply port 17 . The first biomass supplied to the combustion chamber 12 by the first biomass supply section 30 is stirred together with the fluidized medium 15 and combusted.

The second biomass supply port 18a is a supply port that supplies the second biomass into the combustion chamber 12. When the second biomass is fed into the combustion chamber 12, char is generated within the combustion chamber 12. Since the second biomass can be supplied to the combustion chamber 12 via the second biomass supply port 18a, the second biomass can be continuously supplied to the combustion chamber 12. The second biomass supply port 18a is provided in the side wall of the combustion chamber 12. The second biomass supply port 18a is provided downstream of the first biomass supply port 17. Specifically, the second biomass supply port 18a is provided above the first biomass supply port 17 in the vertical direction. Further, the second biomass supply port 18a is provided downstream of the first air supply hole 14. A second biomass supply section 31 that supplies second biomass to the combustion chamber 12 is connected to the second biomass supply port 18a. The second biomass supplied to the combustion chamber 12 by the second biomass supply section 31 is carbonized as described below, and charred material is generated from the second biomass.

The second biomass is heated by combustion of the first biomass through the second biomass supply port 18a, and is delivered to a carbonization region where low-concentration oxygen gas whose oxygen concentration has become lower than air due to the combustion of the first biomass exists. Supplied. The carbonization region is maintained at a temperature and low oxygen concentration suitable for the production of char, and the second biomass is supplied under such a controlled atmosphere. The second biomass is heated by hot gas produced by combustion of the first biomass. Therefore, thermal decomposition of the second biomass proceeds stably, and charcoal can be stably generated from the second biomass.

The properties of the generated char vary depending on conditions such as the type and drying state of the second biomass, the amount of second biomass supplied, the temperature of the carbonization region, and the oxygen concentration of the carbonization region. Therefore, depending on the properties of the carbide to be produced, the conditions of the second biomass supply amount, the temperature of the carbonization region, and the oxygen concentration of the carbonization region may be determined in advance through a trial run.

The exhaust port 19 is an exhaust port that discharges the gas after the first biomass combustion. When char is generated from the second biomass within the combustion chamber 12, the char is also discharged through the outlet 19. The carbide can be discharged from the discharge port 19 along with the combustion gas whose volume has expanded due to combustion. The discharge port 19 is provided above the first air supply hole 14, the second air supply port 16, the first biomass supply port 17, and the second biomass supply port 18a in the vertical direction. Specifically, the exhaust port 19 is provided in the ceiling of the combustion chamber 12 . The discharge port 19 is connected to the first connection channel 36 .

The first biomass and the second biomass may be the same type of biomass, or may be different types of biomass. Biomass may include, for example, organic matter such as wood, herbs, livestock manure, domestic wastewater such as sewage sludge and septic tank sludge, and food waste. The biomass may include at least one of waste biomass and unused biomass. Waste-based biomass may include livestock waste such as chicken manure. The unused biomass may include at least one of inedible parts of agricultural crops, forest residue, bamboo, and bamboo. The inedible part of the agricultural product includes at least one selected from the group consisting of rice husk, rice straw, wheat straw, corn stalk, empty palm fruit bunch (EFB), old palm tree (OPT), and palm kernel husk (PKS). Good too. The biomass may include at least one of herbaceous biomass and woody biomass. The woody biomass may include at least one of thinned wood and pruned branches. Among these, biomass includes at least one selected from the group consisting of rice husks, rice straw, wheat straw, chicken manure, corn stalks, bamboo, bamboo, thinned wood, and pruned branches in terms of abundance and weight. It is preferable.

The first biomass supply section 30 and the second biomass supply section 31 may each include a continuous supply type supply machine such as a screw feeder and a table feeder. Further, the first biomass supply section 30 and the second biomass supply section 31 may include a weight feeder such as a loss-in-weight type feeder or a positive displacement feeder. Further, the amount of second biomass supplied from the second biomass supply section 31 may be greater than the amount of first biomass supplied from the first biomass supply section 30. The amount of the second biomass supplied from the second biomass supply section 31 may be, for example, 2 times or more and 10 times or less the amount of the first biomass supplied from the first biomass supply section 30.

The carbide manufacturing system 1 may include a first crusher 32 and a second crusher 33. The first crusher 32 crushes the first biomass and the second biomass. The second crusher 33 further crushes the second biomass crushed by the first crusher 32. By pulverizing the first biomass with the first pulverizer 32, the first biomass can be pulverized into a size suitable for combustion. Furthermore, by pulverizing the second biomass with the first pulverizer 32 and the second pulverizer 33 to reduce the particle size, the second biomass can be easily carbonized and transferred to the charred material recovery device 40. Can be done. The second biomass supplied through the second biomass supply port 18a may be smaller in size than the first biomass supplied through the first biomass supply port 17. In addition, when the first biomass and the second biomass have optimal sizes, the first biomass and the second biomass do not need to be crushed by the first crusher 32 and the second crusher 33.

The carbide production system 1 may include at least one selected from the group consisting of a magnetic separator, a wind separator, and a particle size separator (not shown). These sorters can remove foreign substances such as metal and concrete pieces from the first biomass supplied by the first biomass supply unit 30 and the second biomass supplied by the second biomass supply unit 31.

The combustion furnace 10 may include a thermometer 34 that measures the temperature in the combustion chamber 12 above the second air supply port 16 in the vertical direction and below the discharge port 19 in the vertical direction. By measuring the temperature of the carbonization region with the thermometer 34, the carbonization temperature can be easily controlled. The temperature of the carbonized region may be about 700°C to 1200°C. By setting the temperature of the carbonization region to 700° C. or higher, carbonization can easily proceed even if the second biomass contains a large amount of water. Further, by setting the temperature of the carbonization region to 1200° C. or lower, components of the second biomass and the like can be prevented from partially melting and adhering to the inner wall of the combustion furnace 10.

The combustion furnace 10 may include an oxygen concentration meter 35 that measures the oxygen concentration in the combustion chamber 12 above the second air supply port 16 in the vertical direction and below the discharge port 19 in the vertical direction. . By measuring the oxygen concentration in the carbonized region with the oxygen concentration meter 35, the oxygen concentration can be easily controlled. The oxygen concentration in the carbonized region may be approximately 0% to 7% by volume. By setting the oxygen concentration to 0% by volume or more, carbide can be easily generated even when the second biomass has a large volatile content. Further, by setting the oxygen concentration to 7% by volume or less, the production of carbon dioxide is promoted through combustion, and it is possible to suppress a reduction in the residual amount of carbon.

The combustion furnace 10 and the carbide recovery device 40 are connected via the first connection flow path 36. The first connection channel 36 is provided with a second biomass supply port 18b that supplies the second biomass into the first connection channel 36. When the second biomass is fed into the first connecting channel 36, char is produced in the first connecting channel 36. Specifically, the second biomass is heated by combustion of the first biomass through the second biomass supply port 18b, and low-concentration oxygen gas whose oxygen concentration is lower than air due to the combustion of the first biomass is supplied. It is fed into the charred area that exists. The gas inside the combustion furnace 10 passes through the first connecting flow path 36, so the atmosphere is high temperature and low in oxygen. By supplying the second biomass under such an atmosphere, charcoal can be stably generated from the second biomass in the same way as when the second biomass is supplied into the combustion chamber 12 through the second biomass supply port 18a. can do.

In this embodiment, as shown in FIGS. 2 and 3, the second biomass supply port 18b is provided at a substantially central portion of the cylindrical portion of the first connection channel 36 when viewed from the central axis direction. The first connecting flow path 36 includes a first cylindrical pipe 36a that is connected to the combustion furnace 10 and extends in the vertical direction, and a second cylindrical pipe 36b that is connected to the carbide recovery device 40 and extends in the horizontal direction. As shown in FIG. 3, when viewed from the direction of the central axis of the second cylindrical tube 36b, the first cylindrical tube 36a is placed at a horizontally different position from the central axis of the second cylindrical tube 36b. The cylindrical tube 36a and the second cylindrical tube 36b are connected. Therefore, as shown by the arrows in FIGS. 2 and 3, the first connecting flow path 36 is configured so that the gas sent from the combustion furnace 10 flows spirally within the second cylindrical pipe 36b. When viewed from the direction of the central axis of the second cylindrical pipe 36b, the second biomass supply port 18b is connected to the first connection flow path 36 so as to substantially coincide with the central axis of the second cylindrical pipe 36b. Therefore, the second biomass is supplied to the center of the spirally flowing gas and flows spirally. Thereby, the residence distance of the second biomass can be increased.

However, in the first connection channel 36, the position where the second biomass supply port 18b is provided is not limited to such a configuration. For example, as shown in FIGS. 4 and 5, the second biomass supply port 18b may be provided on the side wall of the second cylindrical pipe 36b. When the second biomass supply port 18b is provided on the side wall of the second cylindrical pipe 36b, the supplied second biomass falls into the second cylindrical pipe 36b. That is, the second biomass is easily entrained in the internal spiral flow, and biomass with a relatively large particle size is also difficult to fall into the fluidized bed of the combustion furnace 10, so that stable combustion conditions can be maintained within the combustion furnace 10. . Furthermore, since the particle size of the biomass to be supplied can be increased, the degree of freedom in producing carbide can be expanded.

Furthermore, although the first cylindrical tube 36a extends in the vertical direction and the second cylindrical tube 36b extends in the horizontal direction, the present invention is not limited to such a configuration. For example, as shown in FIGS. 6 and 7, the second cylindrical pipe 36b may be provided so as to be inclined downward in the vertical direction from the connection part with the first cylindrical pipe 36a toward the carbide recovery device 40. . Further, in this embodiment, the first cylindrical tube 36a and the second cylindrical tube 36b have a cylindrical shape, but may have an elliptical shape, for example. Furthermore, in the present embodiment, the first cylindrical pipe 36a and the second cylindrical pipe 36b are connected to form an angular L-shape, but the first connection channel 36 has a curved part. The first cylindrical tube 36a and the second cylindrical tube 36b may be connected via.

Furthermore, in the present embodiment, the second biomass supply port 18 includes a second biomass supply port 18a provided in the combustion chamber 12 and a second biomass supply port 18b provided in the first connection channel 36. There is. However, the second biomass supply port 18 may include only either the second biomass supply port 18a or the second biomass supply port 18b. That is, the second biomass supply port 18 only needs to include at least one of the second biomass supply port 18a and the second biomass supply port 18b.

As shown in FIG. 1, the first connection channel 36 may be provided with a third air supply port 37 that supplies air into the first connection channel 36. The temperature within the first connection flow path 36 may become low as energy is consumed by thermally decomposing the second biomass. Further, when the second biomass contains a large amount of water, thermal energy is used to vaporize the water, and the temperature inside the first connecting channel 36 may become low. Therefore, by supplying air into the first connecting channel 36 from the third air supply port 37 and burning a part of the second biomass in the first connecting channel 36, the air in the first connecting channel 36 is A decrease in temperature can be suppressed. Thereby, the inside of the first connection channel 36 can be maintained at a temperature suitable for carbonization.

The third air supply port 37 may be provided in the first connection channel 36 at a position closer to the second biomass supply port 18b than the carbide recovery device 40. Thereby, it is possible to suppress unevenness in the temperature within the first connecting channel 36 from the second biomass supply port 18b to the carbide recovery device 40.

The air flow path 21 is connected to the third air supply port 37. The air flow path 21 branches between the blower 23 and the flow rate adjustment damper 25. The branched air flow path 21 is provided with a flow rate adjustment damper 26 and a flow rate adjustment damper 28. Then, by driving the blower 23 with the flow rate adjustment damper 24, the flow rate adjustment damper 26, and the flow rate adjustment damper 28 open, air is transferred from the air intake port 22 through the third air supply port 37 to the first connection flow path. 36 can be fed continuously.

The carbide recovery device 40 is connected to the combustion furnace 10 and recovers the carbide generated from the second biomass. Although the carbide recovery device 40 may be a powder recovery device such as a bag filter, in this embodiment, the carbide recovery device 40 includes a cyclone. A cyclone is a device that separates and collects carbides using centrifugal force. Gaseous tar derived from thermal decomposition of biomass in the combustion furnace 10 is also supplied to the char recovery device 40 . Since a cyclone can separate gas and carbide without using a filter in a high temperature state where tar does not condense, carbide with little tar attached can be easily recovered.

The cyclone has a supply port 41 to which gas in which carbide is dispersed is supplied, a main body part 42 that centrifugally separates the carbide, a dust collection chamber 43 that collects the carbide, and a cylindrical part that discharges the gas from which the carbide has been removed. A discharge pipe 44 is included. The main body portion 42 includes a cylindrical portion 42a disposed at an upper portion and a conical portion 42b provided vertically below the cylindrical portion 42a. The discharge pipe 44 is arranged inside the cylindrical portion 42a. The carbide falls inside the main body 42 and is collected in the dust collection chamber 43. The gas from which the carbide has been removed is discharged from the carbide recovery device 40 through the exhaust pipe 44 .

A double damper 45 in which two dampers are connected is connected to the dust collection chamber 43. Each damper includes a lid 46, and by opening one lid 46 and closing the other lid 46, carbide can be removed from the carbide recovery device 40 without introducing atmospheric air. Note that, instead of the double damper 45, a rotary take-out device such as a rotary valve may be used. Further, a water sealing device connected to the main body portion 42 may be used as the extraction device. The water seal device may include a water storage tank for storing water. Since one end of the main body part 42 is sealed with water in the water storage tank, the carbide separated in the main body part 42 comes into contact with the water in the water storage tank and is cooled. Note that the above extraction device may be applied to a carbide recovery device 40 other than a cyclone.

The recovered charcoal contains carbon derived from the second biomass. By carbonizing the second biomass without burning it, it is possible to suppress the release of carbon dioxide into the atmosphere. The obtained carbide may be used, for example, as a backfill material in the remains of a quarry. In such a case, the same effect as CCS (carbon dioxide capture and storage) can be obtained. Carbide can also sequester carbon into soil. When used in agricultural fields such as fields, charcoal can not only sequester carbon but also act as a soil conditioner. Since the carbide production system 1 according to the present embodiment can stably control the temperature and oxygen concentration in the carbonization region, the amount of carbon in the carbide and components such as nitrogen, phosphorus, and potassium, which are essential nutrients for plants, can be controlled stably. The amount can also be adjusted arbitrarily. Further, since carbide absorbs light and is easily heated, it may be used as a snow melting agent. Moreover, the carbide can also be used as a deodorizing agent.

The carbide production system 1 may further include a gas utilization device 50 that utilizes gas discharged from the carbide recovery device 40. In this embodiment, the gas utilization device 50 includes a boiler. Specifically, the gas utilization device 50 includes an exhaust heat recovery boiler 51. The exhaust heat recovery boiler 51 recovers the heat of the gas discharged from the carbide recovery device 40 by heat exchange to generate at least one of steam and hot water. The heat recovered by the exhaust heat recovery boiler 51 can be used as thermal energy in a factory or the like.

The gas utilization device 50 is connected to the carbide recovery device 40 via a second connection flow path 52. A fourth air supply port 53 is provided in the second connection channel 52 . The air flow path 21 is connected to the fourth air supply port 53 . The air flow path 21 branches between the blower 23 and the flow rate adjustment damper 25. The branched air flow path 21 is provided with a flow rate adjustment damper 26 and a flow rate adjustment damper 29. Then, by driving the blower 23 with the flow rate adjustment damper 24, the flow rate adjustment damper 26, and the flow rate adjustment damper 29 open, air is transferred from the air intake port 22 through the fourth air supply port 53 to the second connecting flow path. 52 can be continuously supplied. By supplying air into the second connection flow path 52, the remaining combustible components can be burned.

The carbide manufacturing system 1 may include a thermometer 54 that is provided downstream of the fourth air supply port 53 and measures the temperature inside the second connection channel 52. Thereby, the temperature of the gas supplied to the gas utilization device 50 can be managed. Further, the carbide production system 1 may include an oxygen concentration meter 55 that is provided downstream of the fourth air supply port 53 and measures the oxygen concentration inside the second connection channel 52. Thereby, the oxygen concentration of the gas supplied to the gas utilization device 50 can be managed.

The ash separator 56 is connected to the exhaust heat recovery boiler 51. The ash separator 56 removes ash from the gas discharged from the exhaust heat recovery boiler 51. A cyclone 57 is connected to the ash separator 56. The gas from which ash has been separated by the ash separator 56 is supplied to a cyclone 57. Since there is a possibility that a trace amount of fine particles remain in the gas supplied to the cyclone 57, the fine particles can be separated by the cyclone 57 and then released into the atmosphere.

The gas outlet of the cyclone 57 is connected to the dust collection chamber 43 of the carbide recovery device 40 via a cooling gas flow path 58. A flow rate adjusting damper 59 and a circulation cooling fan 60 are provided in the cooling gas passage 58 . Gas is then supplied from the cyclone 57 to the carbide recovery device 40 by driving the circulation cooling fan 60 with the flow rate adjustment damper 59 open. Therefore, the carbide is cooled in the carbide recovery device 40 by gas derived from the gas discharged from the carbide recovery device 40 and cooled by heat exchange in the gas utilization device 50. The carbide that has just been recovered by the carbide recovery device 40 is at a high temperature, and if it comes into contact with air, there is a risk that it will be burned by the oxygen in the air. However, the oxygen concentration of the gas discharged from the carbide recovery device 40 is low. Further, the heat of the gas discharged from the carbide recovery device 40 is recovered and cooled by the gas utilization device 50. Therefore, by using such a gas to cool the recovered carbide, the carbide can be cooled without separately preparing a cooling gas with a low oxygen concentration.

Note that gas with a low oxygen concentration may be introduced into the carbide recovery device 40 at a low temperature of 200° C. or lower using a cooling device (not shown) without using the gas utilization device 50 as in this embodiment. Such a configuration also makes it possible to suppress combustion of the carbide recovered by the carbide recovery device 40. Further, when using the water sealing device as described above, since the carbide can be cooled with water, the carbide can be cooled without using low-temperature gas with a low oxygen concentration.

As described above, the carbide production system 1 according to the present embodiment includes the combustion furnace 10 that has the first biomass supply port 17 that supplies the first biomass and includes the combustion chamber 12 that burns the first biomass with air. There is. The carbide production system 1 includes a carbide recovery device 40 that is connected to the combustion furnace 10 and recovers carbide produced from the second biomass. The second biomass is heated by combustion of the first biomass through the second biomass supply port 18, and is transferred to a carbonization region where low-concentration oxygen gas whose oxygen concentration has become lower than air due to the combustion of the first biomass exists. Supplied. The second biomass supply port 18 is provided downstream of the first biomass supply port 17 .

Furthermore, the method for producing carbide according to the present embodiment includes a step of burning the first biomass supplied to the combustion chamber 12 of the combustion furnace 10 with air. The method for producing carbide includes a carbonization region that is downstream of the first biomass, is heated by the combustion of the first biomass, and contains a low-concentration oxygen gas whose oxygen concentration is lower than that of air due to the combustion of the first biomass. The method includes a step of supplying a second biomass to the second biomass. The carbide production method includes a step of recovering carbide produced from the second biomass using a carbide recovery device 40 connected to the combustion furnace 10 .

Therefore, according to the carbide production system 1 according to the present embodiment, stable carbide can be continuously produced from biomass. For example, biomass raw materials such as rice husks have different moisture concentrations and properties depending on storage conditions, but according to the carbide production system 1 according to the present embodiment, a stable high-temperature atmosphere can be controlled and maintained.

[Second embodiment]
Next, a carbide manufacturing system 1 according to a second embodiment will be described using FIG. 8. The carbide manufacturing system 1 according to the second embodiment differs from the carbide manufacturing system 1 according to the first embodiment in the form of the gas utilization device 50. The carbide production system 1 according to the second embodiment is the same as the first embodiment in other respects, so the explanation will be omitted.

As shown in FIG. 8, the gas utilization device 50 according to the present embodiment includes an exhaust heat recovery boiler 70. The carbide production system 1 also includes a turbine 72 , a generator 73 , an air-cooled steam condenser 74 , and a condensate tank 75 .

A second connection flow path 52 is connected to the exhaust heat recovery boiler 70. The exhaust heat recovery boiler 70 recovers the heat of the gas discharged from the carbide recovery device 40 by heat exchange, and generates steam. The water vapor whose volume has expanded as water vapor passes through the turbine 72 and is used as power to rotate the turbine 72. The turbine 72 is mechanically connected to a generator 73, and is provided so that the generator 73 generates electric power by rotation of the turbine 72. Steam discharged from the turbine 72 is supplied to an air-cooled steam condenser 74. The water vapor supplied to the air-cooled steam condenser 74 is cooled and condensed, and the condensed water is stored in a condensate tank 75. Water in the condensate tank 75 is supplied to the exhaust heat recovery boiler 70 by driving the pump 76 and circulated therein.

The gas discharge port of the exhaust heat recovery boiler 70 is connected to the dust collection chamber 43 of the carbide recovery device 40 via a cooling gas flow path 77. A bag filter 78 , a flow rate adjustment damper 79 , an induction fan 80 , a flow rate adjustment damper 81 , and a circulation cooling fan 82 are connected to the cooling gas flow path 77 from the gas outlet of the exhaust heat recovery boiler 70 to the carbide recovery device. They are provided in this order toward the 40 dust collection chambers 43. Particulates in the gas discharged from the exhaust heat recovery boiler 70 are collected by a bag filter 78. Then, by driving the induction fan 80 with the flow rate adjustment damper 79 open, a part of the gas from which particulates have been removed is discharged into the atmosphere from the chimney 83. Further, by driving the circulation cooling fan 82 with the flow rate adjustment damper 81 open, a part of the gas from which particulates have been removed is supplied to the dust collection chamber 43 of the carbide recovery device 40 . Therefore, the carbide is cooled in the carbide recovery device 40 by gas derived from the gas discharged from the carbide recovery device 40 and cooled by heat exchange in the gas utilization device 50.

According to the carbide production system 1 according to the present embodiment, stable carbide can be continuously produced from biomass, and power can also be generated.

[Third embodiment]
Next, a carbide manufacturing system 1 according to a third embodiment will be described using FIG. 9. The carbide manufacturing system 1 according to the third embodiment differs from the carbide manufacturing system 1 according to the first embodiment in the form of the gas utilization device 50. The carbide manufacturing system 1 according to the third embodiment is the same as the first embodiment in other respects, so the explanation will be omitted.

As shown in FIG. 9, the gas utilization device 50 according to this embodiment includes a coal-fired boiler 90. Further, the carbide production system 1 according to the present embodiment includes a cyclone 97.

The coal-fired boiler 90 is a boiler that uses coal as fuel. A coal feeder 92 supplies coal to a combustion chamber 91 of a coal-fired boiler 90, and an air supply unit 93 supplies air. Specifically, the air supply section 93 includes an air intake port 94, a flow rate adjustment damper 95, and a blower 96, and by driving the blower 96 with the flow rate adjustment damper 95 open, air intake is performed. Air is supplied to the combustion chamber 91 through the port 94 .

A second connection flow path 52 is connected to the coal-fired boiler 90. In this embodiment, unlike the first embodiment, the fourth air supply port 53 is provided at a position closer to the coal-fired boiler 90 than the carbide recovery device 40 in the second connection flow path 52. Therefore, the combustible components discharged from the carbide recovery device 40 can be burned in the coal-fired boiler 90. Since this combustion heat can be recovered by heat exchange in the coal-fired boiler 90, the amount of coal used in the coal-fired boiler 90 can be reduced. Note that instead of the coal-fired boiler 90, a heavy oil-fired boiler or a gas-fired boiler may be used. Even in such a case, fossil fuel consumption can be reduced.

The gas outlet of the coal-fired boiler 90 is connected to a cyclone 97. The gas in the combustion chamber 91 is cooled by heat exchange, and the cooled gas passes through the cyclone 97. In the cyclone 97, particulates are collected and some gas is released from the cyclone 97 into the atmosphere.

The cyclone 97 and the dust collection chamber 43 of the carbide recovery device 40 are connected via a cooling gas flow path 98. A flow rate adjusting damper 99 and a circulation cooling fan 100 are provided in the cooling gas passage 98 . Then, by driving the circulation cooling fan 100 with the flow rate adjustment damper 99 open, a part of the gas from which particulates have been removed is supplied to the dust collection chamber 43 of the carbide recovery device 40. Therefore, the carbide is cooled in the carbide recovery device 40 by gas derived from the gas discharged from the carbide recovery device 40 and cooled by heat exchange in the gas utilization device 50.

According to the carbide production system 1 according to the present embodiment, stable carbide can be continuously produced from biomass, and the use of coal required for the coal-fired boiler 90 can also be reduced.

Note that in the first to third embodiments, one blower 23 is used to supply air to the carbide manufacturing system 1 through a plurality of air supply ports. However, a blower may be disposed upstream of each flow rate adjusting damper, and air may be supplied to the carbide manufacturing system 1 through each air supply port.

The entire contents of Japanese Patent Application No. 2022-102517 (filing date: June 27, 2022) are incorporated herein by reference.

Although several embodiments have been described, it is possible to modify or transform the embodiments based on the content disclosed above. All components of the embodiments described above and all features recited in the claims may be extracted individually and combined insofar as they are not inconsistent with each other.

This disclosure applies, for example, to Goal 2 "End hunger, achieve food security and improved nutrition, and promote sustainable agriculture" and Goal 13 "End hunger, achieve food security and improved nutrition, and promote sustainable agriculture" of the Sustainable Development Goals (SDGs) led by the United Nations. Goal 15: “Take urgent measures to reduce climate change and its impacts” and Goal 15: “Protect, restore and promote the sustainable use of terrestrial ecosystems, sustainably manage forests, combat desertification and can contribute to "preventing and reversing the degradation of biodiversity and halting the loss of biodiversity."

1 Carbide production system 10 Combustion furnace 12 Combustion chamber 17 First biomass supply port 18 Second biomass supply port 36 First connection channel 37 Third air supply port 40 Carbide recovery device 50 Gas utilization device

Claims

A combustion furnace including a combustion chamber that has a first biomass supply port that supplies a first biomass and burns the first biomass with air;
A carbide recovery device connected to the combustion furnace and recovering carbide generated from the second biomass;
Equipped with
The second biomass is heated by combustion of the first biomass through a second biomass supply port provided downstream of the first biomass supply port, and the second biomass is heated by combustion of the first biomass to generate more than the air. A carbide production system in which low-concentration oxygen gas with a low oxygen concentration is supplied to the carbonization region.
The carbide manufacturing system according to claim 1, wherein the combustion furnace is a vertical combustion furnace.
The combustion chamber is provided with the second biomass supply port for supplying the second biomass into the combustion chamber,
The carbide production system according to claim 1 or 2, wherein the carbide is generated within the combustion chamber.
The combustion furnace and the carbide recovery device are connected via a connecting flow path,
The connecting channel is provided with the second biomass supply port for supplying the second biomass into the connecting channel,
The carbide production system according to any one of claims 1 to 3, wherein the carbide is produced within the connecting flow path.
The combustion furnace and the carbide recovery device are connected via a connecting flow path,
The carbide manufacturing system according to any one of claims 1 to 4, wherein the connecting channel is provided with an air supply port for supplying air into the connecting channel.
The carbide production system according to any one of claims 1 to 5, wherein the carbide recovery device includes a cyclone.
Further comprising a gas utilization device that utilizes gas discharged from the carbide recovery device,
The carbide is cooled in the carbide recovery device by gas derived from gas discharged from the carbide recovery device and cooled by heat exchange in the gas utilization device.
6. The carbide production system according to any one of 6.
a step of burning the first biomass supplied to the combustion chamber of the combustion furnace with air;
In a carbonization region that is downstream of the first biomass and is heated by the combustion of the first biomass, and in which there is a low-concentration oxygen gas whose oxygen concentration is lower than that of the air due to the combustion of the first biomass. a step of supplying a second biomass;
Recovering the carbide generated from the second biomass with a carbide recovery device connected to the combustion furnace;
A carbide manufacturing method, including: